JP2009116221A - Assembly method for process cartridge, side plates retaining tool and process cartridge - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an assembly method for a process cartridge in which space Ds when an image carrier and a developer carrier are attached can be correctly derived, side plates retaining tool and the process cartridge which is manufactured by using the method and the tool. <P>SOLUTION: The assembly method for the process cartridge is provided with at least four types of members of the image carrier, the developer carrier, a pair of side plates, and a housing retaining the pair of side plates. The pair of side plates has a spacing adjusting mechanism for adjusting the space between the image carrier and the developer carrier. Measuring and adjustment of the space is carried out by the side plates retaining tool which retains at least the three types of members which are the image carrier, the developer carrier and the pair of side plates and the space measuring tool measuring the space. The three types of members for which the measuring and the adjustment of space is completed are assembled to the housing as one set. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an assembling method, a side plate holder, and a process cartridge assembled by using them, in a process cartridge in an image forming apparatus using an electrophotographic system.

  Among image forming apparatuses using an electrophotographic system, an image forming apparatus of a type in which an apparatus having a unit structure called a process cartridge is detachably incorporated in an image forming apparatus is widely used.

  The process cartridge here is a unit in which at least a developing device having a developer carrier and an image carrier are integrally formed. In addition, a plurality of process means such as a charging device and a cleaning device are used. There is also an integrated unit. By regularly replacing the process cartridge, the consumables can be easily updated, and the image forming apparatus can be easily maintained.

  On the other hand, the required quality for the image quality of an image forming apparatus using an electrophotographic system has been increasing in recent years. However, as an element that greatly affects the image quality such as image density, the interval between the image carrier and the developer carrier (hereinafter referred to as the image carrier) Ds).

  That is, if the distance Ds is too large, there are problems that the image density is too low, or that it is difficult for toner to move from the developer carrier to the image carrier during development, resulting in density unevenness. On the other hand, if the distance Ds is too small, the image density is too high, or the developer and the toner are clogged with the two-component developer of the carrier and the toner, and the leakage from the developing roller to the photosensitive member is caused with the one-component developer of only the toner. There is a problem that occurs.

  As described above, the distance Ds between the image carrier and the developer carrier is an extremely important management item in terms of image quality. In addition, due to recent demands for high durability and high image quality, there is an increasing need to guarantee the interval Ds with higher accuracy.

  Conventionally, efforts have been made to increase the accuracy of the interval Ds by using a component configuration that uses high processing accuracy and expensive materials. However, in recent years, it is necessary to guarantee accuracy in an area where component accuracy alone is insufficient. It is coming.

  Methods that have been attempted to set the value of the distance Ds constant include a method of directly measuring the distance Ds using a gap gauge, or through a transparent window provided in the process cartridge using a light beam. A method of indirectly measuring the distance Ds has been common (see, for example, Patent Document 1).

  However, no matter which method is used, measurement is performed so as not to interfere with surrounding members and damage the surface of the image carrier. When adjustment is necessary, there is a problem that it takes time to remove and reassemble.

  On the other hand, when the distance Ds needs to be readjusted as a result of the measurement, there are known cam mechanisms and screw mechanisms as the readjustment mechanism, but the mechanism using the spacer has a simple configuration such as screw loosening. Widely used as a reliable system with few problems.

  However, in a mechanism using a spacer, when the readjustment is necessary, the spacer is increased or decreased, so that generally a work for removing the bearing member or the like is required.

  Even in a system using a cam mechanism or screw mechanism, a part of the mechanism must be removed in order to reliably perform adjustment work or fixing work after adjustment due to the influence of the surrounding space, etc. There were many.

  In general, a process cartridge is integrally assembled with many mechanisms and members such as a housing, a photosensitive drum, a developing roller, various rollers, blades, and a cleaning device. It took effort.

For these problems, a reference device in which a reference pin is set up at a position corresponding to the distance Ds between the rotation shafts of the image carrier and the developer carrier is used, and the position of the bearing member fitted to the two rotation shafts is set on the side plate. A technique has been proposed in which the distance Ds is determined as described above (see, for example, Patent Document 2).
Japanese Patent Laid-Open No. 5-323893 JP-A-10-133541

  However, in the technique described in Patent Document 1, although the design interval Ds can be correctly obtained at the position of the bearing member on the side plate by the reference unit, the image carrier and the developer carrier are actually used on the side plate. Whether or not the distance Ds when attached is a correct value becomes a problem.

  This is because the actually produced image carrier and developer carrier have variations such as variations in outer diameter, variations in roundness and cylindricality, and fluctuations between the rotating shaft and the outer periphery. There are variations in the inner diameter, roundness, and cylindricity of the bearing member to which the two rotating shafts are fitted.

  Therefore, there is no guarantee that the distance Ds will be correct when the image carrier and developer carrier are actually attached to the side plate and further attached to the housing.

  SUMMARY OF THE INVENTION An object of the present invention is to solve the above-described problems and to provide a process cartridge assembling method, a side plate holder, and the like, which can correctly obtain the distance Ds when the image carrier and developer carrier are actually attached. The present invention is to provide a process cartridge assembled by using the above.

  The object of the present invention can be achieved by using a method, jig and process cartridge having the following constitution.

1. An image carrier, a developer carrier that supplies developer to the image carrier, a pair of side plates that hold the image carrier and the developer carrier, and a housing that holds the pair of side plates A method of assembling a process cartridge having at least four members,
Each of the pair of side plates has an interval adjustment mechanism that adjusts an interval between the image carrier and the developer carrier,
The measurement of the interval and the adjustment performed if necessary include a side plate holding jig that holds at least three members of the image carrier, the developer carrier, and the pair of side plates, and an interval for measuring the interval. Done with measuring instruments,
At least three kinds of members of the image carrier, the developer carrier, and the pair of side plates, which have been measured and adjusted if necessary, are assembled to the housing as a set. Process cartridge assembly method.

  2. Each of the pair of side plates includes a bearing member that rotatably holds one of the rotation shafts of the image carrier and the developer carrier and fits the other rotation shaft to the rotation shaft. 2. The process cartridge assembling method according to 1, wherein the distance between the two rotating shafts is adjustable by holding the position adjustable.

  3. 3. The process cartridge assembling method according to 1 or 2, wherein a spacer is used for adjusting the distance.

  4. A process cartridge side plate holding jig which is used in the process cartridge assembling method according to 1 or 2.

5). Process cartridge having at least three members: an image carrier, a developer carrier for supplying a developer to the image carrier, and a pair of side plates for holding the image carrier and the developer carrier Because
The process cartridge includes the pair of side plates that rotatably hold the image carrier and the developer carrier through respective rotation shafts.
Each of the pair of side plates has two rotation shaft holding means for holding two rotation shafts of a rotation shaft of the image carrier and a rotation shaft of the developer carrier,
At least one of the two rotating shaft holding means has a configuration capable of adjusting an interval between the two rotating shafts,
A process cartridge assembled by the process cartridge assembling method according to any one of claims 1 to 3.

  6). 6. The process cartridge according to 5, wherein the pair of side plates are made of a resin material having a friction coefficient larger than 0 and 0.6 or less.

  With the configuration in which measurement is performed using parts actually used according to the present invention, even when an image carrier and a developer carrier having variations for each part are attached to individual process cartridges, the variations are reduced. It is possible to correct and set the interval Ds appropriately.

  That is, by using the assembling method and member according to the present invention, a process cartridge that enables high-quality image formation without image density unevenness and developer clogging, and an interval adjusting method for the interval Ds are provided for each process cartridge. Can be provided stably.

  In addition, since adjustment and removal work at the part level before assembly can be performed, inspection, adjustment, and repair work can be performed efficiently, and there are few restrictions on the space around the distance Ds, so measurement is possible. And adjustment work is easy, design freedom is high, and downsizing of the device can be expected.

  The present invention will be described based on the illustrated embodiment, but the present invention is not limited to the embodiment.

  FIG. 1 is a cross-sectional view for explaining a configuration of an example of an embodiment of a process cartridge according to the present invention. FIG. 1 is a configuration diagram showing an embodiment of a process cartridge using a one-component developer, but the present invention is also applicable to a process cartridge using a two-component developer.

  The process cartridge 100 includes a photosensitive drum 10 as an image carrier, a charger 11, a developing device 13 as a developer carrier, and a photosensitive cleaner 15.

  The skeleton of the process cartridge 100 includes a cleaner / drum frame 150 serving as a first housing serving as a skeleton of the photoconductor cleaner 15, and a developing frame 130 serving as a second housing serving as a skeleton of the developing device 13. The charger 11 is held by a cleaner / drum frame 150.

  The cleaner / drum frame 150 and the developing frame 130 hold a pair of side plates 20 and 21 in the vicinity of both ends in the rotation axis direction of the photosensitive drum 10, and the cleaner / drum frame 150, the developing frame 130, and the pair of side plates 20 and 21. The side plates 20 and 21 are integrally coupled.

  The photosensitive drum 10 is rotatably held by the side plates 20 and 21 in the vicinity of both ends of the rotating shaft 10a via a bearing member described later.

  A blade holding member 152 for holding the cleaning blade 151 is disposed on the cleaner / drum frame 150 of the photoconductor cleaner 15.

  The cleaning blade 151 is made of an elastic urethane resin or the like, and is disposed at a position in pressure contact with the photosensitive drum, and removes toner remaining after the primary transfer on the photosensitive drum 10. The blade holding member 152 is made of a material such as metal.

  The developing device 13 is a device that performs development by supplying toner to the surface of the photosensitive drum 10 using, for example, a one-component developer composed only of toner.

  The developing device 13 includes a developing frame 130, a developing roller 131, a regulating blade 134, a blade holder 135, a supply roller 136, and a rotating body 137.

  The developing roller 131 is rotatably held by the side plates 20 and 21 through a bearing member described later in the vicinity of both ends of the rotation shaft. Further, the developing roller 131 includes, for example, a conductive cylindrical base and an elastic layer formed on the outer periphery of the base using a substance having high hardness such as silicone rubber. The regulating blade 134 is attached at a position where the tip is in pressure contact with the developing roller 131, and regulates the amount of toner attached on the developing roller 131.

  A mechanism for adjusting the distance Ds between the developing roller 131 and the photosensitive drum 10 will be described later.

  The supply roller 136 disposed at a position for pressing the developing roller 131 is rotationally driven in the same direction as the developing roller 131 (counterclockwise direction in the drawing) by a motor (not shown). The supply roller 136 has a conductive cylindrical base and a foamed layer formed of urethane foam or the like on the outer periphery of the base.

  A rotating body 137 for agitating the developer is provided inside the developing frame 130, and a film-like conveying blade is attached to the rotating body 137, and the developer is removed by the rotation of the rotating body 137 in the arrow direction. Transport. The developer conveyed by the conveying blade is supplied to the supply roller 136 through an opening KB provided in the partition wall 102b that divides the inside of the developing frame 130 into two.

  During image formation, the developing roller 131 is driven to rotate in the direction of the arrow, and the developer is supplied onto the developing roller 131 by the rotation of the supply roller 136. The developer supplied onto the developing roller 131 is thinned by the regulating blade 134 and then conveyed to a region facing the image carrier to be used for developing the electrostatic latent image on the image carrier. The developer that has not been used for development is scraped and collected from the developing roller 131 by the supply roller 136 as the developing roller 131 rotates.

  So far, the configuration of the process cartridge has been described based on the one using a one-component developer, but the configuration of the process cartridge using the two-component developer is similar to the configuration of the process cartridge using the one-component developer. Therefore, the description is omitted.

  FIG. 2 is a schematic configuration diagram showing an example of an embodiment of a side plate having a process cartridge interval adjusting mechanism according to the present invention.

  In FIG. 2, a pair of side plates 20 and 21 are integrally coupled together with the cleaner / drum frame 150 and the developing frame 130 of FIG. 1, and a developing roller which is a rotating member in the photosensitive drum 10 and the developing device 13. 131, the supply roller 136, and the rotating body 137 are rotatably held.

  The photosensitive drum 10 is rotatably held by a pair of bearing members 30 fixed to the holes 20a and 21a of the side plates 20 and 21 at both ends of the rotating shaft 10a.

  The developing roller 131 is rotatably fitted to and held by a pair of bearing members 31 whose positions near both ends of the rotation shaft are held in the long holes 20b and 21b of the side plates 20 and 21 so as to be positionally adjustable.

  The bearing member 31 has a fitting portion with the long holes 20b and 21b formed in an oval shape and is slidably held in the longitudinal direction of the long holes 20b and 21b.

  The longitudinal directions of the long holes 20b and 21b of the pair of side plates 20 and 21 extend toward the holes 20a and 21a, and the photosensitive drum 10 is constituted by the spacer 35 and the long holes 20b and 21b constituting a part of the interval adjusting mechanism. The distance Ds between the developing roller 131 and the developing roller 131 can be adjusted.

  The distance Ds in this embodiment is adjusted by the spacer 35, and one sheet is provided on the side closer to the holes 20a and 21a in the longitudinal direction of the long holes 20b and 21b of the pair of side plates 20 and 21, respectively. The above spacer 35 is inserted. In the embodiment, the spacer 35 is a member made of a PET film having a Rockwell hardness of 80 or more (one piece of thickness 25 μm). Usually, since the reference value of the distance Ds is about 0.45 mm to 0.55 mm, it is considered that about 25 μm is appropriate as the thickness of one spacer 35.

  The other part of the interval adjusting mechanism includes a pair of screw members 23 and a pair of screw member receivers 22 that hold the pair. A pair of screw member receivers 22 that hold the pair of screw members 23 by screw holes (not shown) are integrally fixed to the side plates 20 and 21 on the side opposite to the holes 20a and 21a of the long holes 20b and 21b.

  The pair of screw members 23 abuts the screw tips on the side portions of the bearing member 35 as a rotating shaft holding means slidably held in the long holes 20b and 21b, and rotates the screw to show the bearing member 35. 2 is moved in the A direction and pressed against the spacer side to determine the value of the distance Ds.

  In the embodiment of the present invention, the spacer 35 is used as the interval adjusting mechanism. However, the cam is formed by adjusting the position of one bearing member in the axial direction with a pair of screws, or by rotating the eccentric cam. You may use the cam system etc. which adjust the position of the contacted bearing member.

  The supply roller 136 and the rotating body 137 are rotatably held in the vicinity of both ends of the rotating shaft by bearing members (no reference numerals) fixed to the pair of side plates 20 and 21.

  Reference numeral 40 denotes a light emitting element that emits a laser beam or the like for measuring the distance Ds between the photosensitive drum 10 and the developing roller 131, and reference numeral 41 denotes a light receiving element. The light emitting element 40 and the light receiving element 41 are distance measuring tools as one measuring tool according to the present invention for measuring the distance Ds between the image carrier and the developer carrier. In the embodiment, as the light-emitting element 40 and the light-receiving element 41, elements attached to a high-speed and high-precision digital dimension measuring device (manufactured by Keyence Corporation, LED method, model LS-7030M) are used. The procedure for measuring the distance Ds will be described later.

  FIG. 3 is a schematic configuration diagram showing a state in which three members of the photosensitive drum, the developing roller, and the pair of side plates according to the present invention are mounted on the side plate holding jig.

  A side plate holding jig 50 as another measuring tool according to the present invention holds a pair of side plates 20 and 21 that hold the photosensitive drum 10 and the developing roller 131 via bearing members 30 and 31. The pair of side plates 20 and 21 are attached to the side plate holding jig 50 by guide pins or clamps (not shown) provided in the side plate holding jig 50.

  Since the interval adjusting method according to the present invention is performed by attaching only three kinds of members of the photosensitive drum 10, the developing roller 131, and the side plates 20 and 21 to the side plate holding jig 50, the arrangement of the interval measuring tools 40 and 41 is arranged. In this regard, there is an advantage that there is no member that obstructs measurement such as a housing around.

  As in the present invention, the configuration in which the distance Ds is measured before the pair of side plates 20 and 21 are assembled to the cleaner / drum frame 150 or the developing frame 130, which is the housing, is the distance Ds when assembled to the housing. There are concerns about changes in values. However, in the experiment result by the present inventor, when the distance between the axes of the two rotating shafts is 15 mm, even if the pair of side plates 20 and 21 are inclined by 1 ° with respect to the housing, the influence on the variation in the distance Ds is about 2 μm. It is considered that there is little influence on the reference value 0.45 mm to 0.55 mm of the distance Ds.

  In the present embodiment, the photosensitive drum 10 is held on the pair of side plates 20 and 21 according to the present invention via the bearing member 30, but the material of the side plates 20 and 21 is made of a low friction coefficient. It is also possible to adopt a configuration in which the resin material is used and the bearing member 30 is not used. In this case, the rotating shaft holding means for holding the rotating shaft 10a of the photosensitive drum 10 is a fitting hole formed in the side plates 20 and 21 that are directly fitted to the rotating shaft 10a.

  Examples of applicable resin materials include PS (polystyrene) and PPS (polyphenylene sulfide) having a friction coefficient of 0.6 or less.

  For the side plates 20 and 21 manufactured using these resin materials, the rotating shaft 10a of the photosensitive drum 10 is directly fitted into the fitting holes formed in the side plates 20 and 21, and the photosensitive drum 10 is rotatably held. It is the composition of doing.

  With this configuration, since the pair of bearing members 30 can be omitted, an increase in error due to a variation in dimensional tolerance between the bearing members 30 and the fitting holes of the side plates 20 and 21 and an increase in the cost of the bearing members 30 are expected. it can.

  FIG. 4 is a flowchart for explaining the adjustment procedure of the interval Ds according to the present invention.

  The procedure for adjusting the distance Ds will be described with reference to FIGS.

  First, the three members of the photosensitive drum 10, the developing roller 131, and the pair of side plates 20, 21 are mounted on the side plate holding jig 50 (step S1). At this time, the photosensitive drum 10 and the developing roller 131 are previously incorporated into the pair of side plates 20 and 21 via the bearing members 30 and 31, and the pair of side plates 20 and 21 holding the photosensitive drum 10 and the developing roller 131 are mounted. Attached to the side plate holding jig 50.

  The distance Ds between the photosensitive drum 10 and the developing roller 131 is measured using the light emitting element 40 and the light receiving element 41 as the distance measuring tool (step S2).

  It is confirmed whether or not the value of the measured interval Ds is within a preset reference value range (step S3).

  When the value of the interval Ds is not within the range of the reference value (No at Step S3), the process proceeds to Step S4, and the interval Ds is readjusted (Step S4). The readjustment of the distance Ds is performed by removing three members of the photosensitive drum 10, the developing roller 131, and the pair of side plates 20, 21 from the side plate holding jig 50, and increasing or decreasing the number of spacers 35. After the distance Ds is readjusted, the three types of members are mounted on the side plate holding jig 50 again, the process returns to step S2 to measure the distance Ds, and the operations in steps S2 to S4 are performed until the distance Ds falls within the reference value range. repeat.

  When the value of the interval Ds is within the range of the reference value (Yes at Step S3), the process proceeds to Step S5. In step 5, three members of the passed photosensitive drum 10, developing roller 131, and pair of side plates 20, 21 are attached to the housing as a set, and the process cartridge is completed (step S5).

  If the distance adjustment method according to the present invention is used, even if the measurement result of the distance Ds and the readjustment of the distance Ds are required, the photosensitive drum 10, the developing roller 131, and the pair of side plates 20, 21 are used. There is an advantage that the number of work steps can be reduced because only the members need to be removed.

  Even if the outer diameter and the roundness of the photosensitive drum 10 and the developing roller 131 vary, the photosensitive drum 10, the developing roller 131, and the side plates 20 and 21 that are actually used are used as one set, and the distance Ds. Since this is measured, the influence of variation can be eliminated.

  In the present embodiment, the bearing member 30 of the photosensitive drum 10 is fixed to the holes 20a and 21a of the side plates 20 and 21 with respect to the side plates 20 and 21, and the bearing member 31 of the developing roller 131 is fixed to the long holes of the side plates 20 and 21. Although it was set as the structure hold | maintained to 20b and 21b so that position adjustment is possible, the reverse structure may be sufficient.

  That is, the bearing member 31 of the developing roller 131 is fixed to the holes (not shown) of the side plates 20 and 21 with respect to the side plates 20 and 21, and the position of the bearing member 30 of the photosensitive drum 10 is adjusted to the long holes (not shown) of the side plates 20 and 21. It is the structure which hold | maintains possible.

  In this configuration, there is a problem that the charger 11 and the photoconductor cleaner 15 must be moved integrally with the movement of the position of the photoconductor drum 10, but in order to fix the developing roller 131, There is also an advantage that the positional relationship with the regulating blade 134 is not affected.

It is sectional drawing for demonstrating the structure about an example of embodiment of the process cartridge which concerns on this invention. It is a schematic block diagram which shows an example of embodiment of the side plate which has the space | interval adjustment mechanism of the process cartridge which concerns on this invention. It is a schematic block diagram which shows the state which mounted | wore the side plate holding jig with the photoconductor drum, developing roller, and side plate which concern on this invention. It is a flowchart for demonstrating the adjustment procedure of the space | interval Ds which concerns on this invention.

Explanation of symbols

10 Photosensitive drum (image carrier)
DESCRIPTION OF SYMBOLS 13 Developing apparatus 15 Photoconductor cleaner 20, 21 Side plate 22 Screw member receiver 23 Screw member 30, 31 Bearing member 35 Spacer 40 Light emitting element (space measuring tool)
41 Light receiving element (interval measuring tool)
50 Side plate holding jig 131 Developing roller (developer carrier)
Ds interval (interval between image carrier and developer carrier)

Claims (6)

An image carrier, a developer carrier that supplies developer to the image carrier, a pair of side plates that hold the image carrier and the developer carrier, and a housing that holds the pair of side plates A method of assembling a process cartridge having at least four members,
Each of the pair of side plates has an interval adjustment mechanism that adjusts an interval between the image carrier and the developer carrier,
The measurement of the interval and the adjustment performed if necessary include a side plate holding jig that holds at least three members of the image carrier, the developer carrier, and the pair of side plates, and an interval for measuring the interval. Done with measuring instruments,
At least three kinds of members of the image carrier, the developer carrier, and the pair of side plates, which have been measured and adjusted if necessary, are assembled to the housing as a set. Process cartridge assembly method. Each of the pair of side plates includes a bearing member that rotatably holds one of the rotation shafts of the image carrier and the developer carrier and fits the other rotation shaft to the rotation shaft. 2. The process cartridge assembling method according to claim 1, wherein the distance between the two rotating shafts can be adjusted by holding the position adjustable. 3. The process cartridge assembling method according to claim 1, wherein a spacer is used for adjusting the distance. A side cartridge holding jig for a process cartridge, which is used in the method for assembling a process cartridge according to claim 1. Process cartridge having at least three members: an image carrier, a developer carrier for supplying a developer to the image carrier, and a pair of side plates that hold the image carrier and the developer carrier Because
The process cartridge includes the pair of side plates that rotatably hold the image carrier and the developer carrier through respective rotation shafts.
Each of the pair of side plates has two rotating shaft holding means for holding two rotating shafts of the rotating shaft of the image carrier and the rotating shaft of the developer carrier,
At least one of the two rotating shaft holding means has a configuration capable of adjusting an interval between the two rotating shafts,
A process cartridge assembled by the process cartridge assembling method according to any one of claims 1 to 3. 6. The process cartridge according to claim 5, wherein the pair of side plates are made of a resin material having a friction coefficient larger than 0 and 0.6 or less.

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